Vehicles operating in an autonomous mode (e.g., driverless) can relieve occupants, especially the driver, from some driving-related responsibilities. When operating in an autonomous mode, the vehicle can navigate to various locations using onboard sensors, allowing the vehicle to travel with minimal human interaction or in some cases without any passengers.
Typically, an autonomous driving vehicle (ADV) can operate either in a manual driving mode or in an autonomous driving mode. In a manual driving mode, a human driver takes control of the vehicle. There are scenarios when an ADV switches out of an autonomous driving mode while the vehicle is running and needs to reenter the autonomous driving mode. When the vehicle reenters the autonomous driving mode from the manual driving mode, passengers may experience sudden acceleration or deceleration during the driving mode transition. This is due to the sudden jumps of velocity or acceleration/deceleration reference during the driving mode transition. This would ultimately cause discontinuity in an output of a controller and therefore cause sudden acceleration or deceleration changes during the driving mode transition. The bumps such as sudden changes of speeds may occur during this reentering stage that may cause passengers uncomfortable.